New Yorkers who do not identify as either male or female may soon have the option to change their birth certificate to a third category.

Under a proposal announced by City Council Speaker Corey Johnson and Mayor Bill de Blasio, adults will have the option to change their given gender to “X.” The proposal would also remove a rule requiring a letter from a medical or mental health professional to change the gender on a birth certificate.

“You don’t need a doctor to tell you who you are and you shouldn’t need a doctor to change your birth certificate to reflect your true self. This groundbreaking legislation will make New York birth certificates more inclusive for all and will send a powerful signal to the world that New York City government works for everyone,” Johnson said in a statement.

The proposal would only affect adults and does not change the options on birth certificates for newborns, a City Council spokeswoman said. Currently, there is a “undetermined or unknown” option for the gender at birth, according to the AP.

“Transgender New Yorkers, like everyone else, should have birth certificates that reflect their true gender identity,” Health Commissioner Dr. Mary Bassett said in a statement. “By allowing self-attestation and ‘X’, the Health Department and City Council are reaffirming our commitment to the self-determination of the transgender and gender non-conforming community.”

The city’s Board of Health will consider the proposal at a meeting on Tuesday. If the board agrees, there will be a hearing on the changes in July and a vote in September, city officials said.

In 2014, the City Council and city health department approved an amendment to remove a requirement for surgery to change the gender on a birth certificate.

California, Oregon and Washington all have a third option on their birth certificates, the AP reported.